#0  SAMPLE_BUFFER::multiply_by (this=0x0, factor=0.891250968)
    at samplebuffer.cpp:358
#1  0x00000000004ba106 in CHAIN::process (this=0x7fffeca88510)
    at eca-chain.cpp:748
#2  0x00000000005562ec in ECA_ENGINE::process_chains (this=0x7fffec79a750)
    at eca-engine.cpp:1647
#3  0x000000000055cf8e in ECA_ENGINE::engine_iteration (this=0x7fffec79a750)
    at eca-engine.cpp:654
#4  0x0000000000534584 in eca_jack_process_engine_iteration (nframes=128,
    arg=<value optimized out>) at audioio_jack_manager.cpp:457
#5  0x0000000000534808 in eca_jack_process_timebase_slave (nframes=128,
    arg=0x7fffec895330) at audioio_jack_manager.cpp:565
#6  eca_jack_process_callback (nframes=128, arg=0x7fffec895330)
    at audioio_jack_manager.cpp:403
#7  0x00007ffff6a3e2d2 in ?? () from /usr/lib/libjack.so.0
#8  0x00007ffff6a53ea0 in ?? () from /usr/lib/libjack.so.0
#9  0x00007ffff5f6d8ca in start_thread () from /lib/libpthread.so.0
#10 0x00007ffff552886d in clone () from /lib/libc.so.6
#11 0x0000000000000000 in ?? ()